Range finder adapter



Aug. 19, 1952 G, R, PETERSON 2,607,275

v RANGE FINDER ADAPTER Filed Nov. 28, 1947 :im www,

Gijcorneq Patented Aug. 19, 1952 UNITED STATES PATENT OFFICE Application November 28, 1947, Serial No. 788,'539

1 Claim.

This invention relates to photographic equipment, and more particularly to a rangender adapter which may bev attached to a camera in conjunction with the mounting thereon of special lenses.

Cameras of the class to which this invention relates are equipped with built-in rangefinder apparatus whereby the user may view the object to be photographed and adjust the apparatus to obtain a reading in feet or meters of the distance of the object from the camera. Visual indication, such as the split image or like device, is used in determining the range. When the range reading has been obtained, the lens may be positioned in accordance therewith, although in some cameras the lens is extended or retracted simultaneously with and in response to adjustment of the rangender apparatus. The rangender apparatus bears a fixed relation in its scope to the focal range of thev lens supplied with the camera. This lens is often supplemented by special lenses for close-up work, as for copying and for portraits, which combination of lenses have a range not conforming` to the scope of the rangelnder mechanism.

Accordingly, it has not been possible heretofore to make use of the rangender mechanism of a camera when working with supplementary lenses. VSuch difficulty is completely eliminated by use of adapters embodying the present invention.

The primary object of the invention is to provide adapters for camera rangending mechanisms' having the aforementioned advantageous features, which may be economically manufaotured for use in conjunction with different cameras and lenses.

Another object of the invention is to enable the rangender apparatus of a camera to be adapted for special uses by applying to the exterior of the camera a simple and inexpensive adapter.

A further object of the invention is to obtain a rangennder adapter which may be clipped or otherwise removably fastened to a camera and which will present in front of a sighting window a glass prism for foreshortening the line of vision.

Still another object is to obtain a rangeflnder adapter which may be variably formed for use in varying types of cameras, and which in one form may superimpose one prism upon another for selective use thereof.

A further object of the invention is to provide a rangender adapter embodying the advantageous structuralv features,l the inherent meritorious characteristics and the mode of operation herein set forth, or their equivalents.

With `the above primary and other incidental objects in view asvv will more fully appear inthe specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereofr and the mode of operation, as hereinafter described or illustrated in the accompanying drawings, or their equivalents;

In the accompanying drawing, wherein, is shown thepreferred but obviously notnecessarily the `only form of embodiment of the invention:

Fig. 1 is a view inperspe'ctive of avcamera equipped with a rangefinder adapter according-to one form of the invention;

Fig. 2y is a detail View in perspectiveV of the rangender adapter of Fig. 1;

Fig. 3 is a fragmentary view in perspective of arangender adapterk according to a second form of the invention; and

Fig. 4 isa schematic view of a camera equipped with a rangennder adapter according to the present invention, showing by means of dotted lines how the adapter' functions to' shifty thev scope of the rangeiinder' apparatus.

Like parts are indicated by similar characters of reference throughout the severalviews:

Referring to the drawings, in Fig. 1 isshown a commercially known cameracomprisingacasing I 0 madeup of interconnected sections I I and I2. Extending4 through the frontvof the casing section II is a telescopic mountingv I3 for a lens I4. The section I2 contains the rangeflnder mechanism and'objective viewer. The knobs I5 and I6 projecting therefrom permit adjustment of the film.

In the front of the section I2 are a pair of spaced openings containing rangender windows I'I and I3. A third window I9, between the windows II and IB, is used in conjunction with or alternatively to the rangennder windows for objective sighting.

According to the well-known construction and manner of use of the ycamera of Fig. l, the rangefinder mechanism further includes an eye opening in the opposite or rear face of section I2, and adjustable mirror mechanism within the casing for directing the vision of the viewer through the windows I'I and I8. The windows II and I8 are Xed and preformed in a determined relation to the focal length of the lens I4 with which the camera is ordinarily equipped. Thus, within the range of the camera lens, the mirror mechanism of the rangender apparatus may be adjusted for an accurate reading of the range and the lens mounting I3 thereupon be retracted or extended to conform to such reading.

In adapting the camera for close-up work, for example copying or portraits, the conventional lens assembly is supplemented by a special lens, the pair of lenses having together a focal range inside the inner limit of the eld of use of the rangending apparatus. 'I'o adapt the rangefnder apparatus for use with such special lenses there is provided an accesory for shortening the intersection of sight through the windows I1 and I8.

According to one form of the invention, such accessory comprises a spring clip which may be variably shaped and arranged to conform tothe varying camera, constructions. In the clip form shown in Figs. 1 and 2, the accessory or adapter comprises a strip of spring metal 2| having turned over end Iportions 22 and 23. The clip is attachable to the top of the casing section I2, with the end portions 22 and 23 respectively embracing the rear and front of the section.

In use the clip is positioned with end portion 22 thereof covering the rangender eye opening at the rear of the camera and with end portion 23 covering Window I8 at the front of the camera. Within end portion 22 is an opening 24 for registry with the eye opening, whilewithin end portion 23, in registry with window I8, is a wedge shaped prism 25. The prism 25, as shown in Fig. 4,` foreshortens the line of sight through the win dow I 8 so as to move the area of intersection with the line of sight through window I1 from point A to point B.

A rangender adapter according to the invention may assume other forms than as shown in Figs. l and 2. In Fig. 3, for example, is illustrated a clip 26 which may be similar to the clip 2l, but which mounts on the front end 23 thereof a frame 21 holding a prism 28. The frame 21 in turn provides a hinged mounting for a second frame 29 holding a prism 3l. The frame 29 may be swung to positions in front of prism 28 or out of line therewith in order that the rangeiinder apparatus may be selectively adapted for use in a variety of focal ranges.

From the above description it will be apparent that there is thus provided a device of the charb acter described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has been described in language more or less specic as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise the preferred form of several modes of putting the invention into eiIect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claim.

Having thus described my invention, I claim:

In a camera having rangender apparatus including spaced apart sight windows constructed and arranged for a sight range conforming to the focal length of the camera lens, an adapter for shortening said sight range to correspond to the shorter focal length of attachable portrait lenses or the like, comprising a clip constructed and arranged for detachable mounting upon the camera, said clip comprising an elongated portion for engagement with the upper end of the camera and turned over end portionsy one of said turned over end portions having an opening therein, prisms mounted on said turned over end portions in alignment with said opening, said prisms being mounted in superimposed relation one upon another for cooperation with said sight opening for foreshortening the intersection of sight through said windows, and a hinged mounting for the outer prism permitting said prism to be moved selectively into and out of effective position.

GIEN ROBERT PETERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 783,665 Avril Feb. 28, 1905 1,675,555 Howell July 3, 1928 1,854,665 Parker Apr. 19, 1932 1,930,432 Barnaclt Oct. 10, v1933 2,041,633 Barnack May 19, 1936 2,186,206 Posner Jan. 9, 1940 2,310,307 Montgomery Feb. 9, 1943 2,327,859 Bolsey Aug. 24, 1943 2,369,751 Stegeman Feb. 26, 1945 FOREIGN PATENTS Number Country Date 509,424 Great Britain July 14, 1939 849,485 France Aug, 2l, 1939 

